Process: Fix incorrect overriding of transition_failed

The `Process` class intended to override the `transition_failed` method
of the `StateMachine` base class, but accidentally implemented the
method `transition_excepted`, which was therefore never called.

src/plumpy/base/state_machine.py

@@ -338,16 +338,14 @@ def transition_to(self, new_state: Union[Hashable, State, Type[State]], *args: A
             self._transition_failing = False
             self._transitioning = False
 
-    @staticmethod
-    def transition_failed(
-        initial_state: Hashable, final_state: Hashable, exception: Exception, trace: TracebackType
+    def transition_failed(  # pylint: disable=no-self-use
+        self, initial_state: Hashable, final_state: Hashable, exception: Exception, trace: TracebackType
     ) -> None:
-        """
-        Called when a state transitions fails.  This method can be overwritten
-        to change the default behaviour which is to raise the exception.
+        """Called when a state transitions fails.
 
-        :param exception: The transition failed exception
+        This method can be overwritten to change the default behaviour which is to raise the exception.
 
+        :param exception: The transition failed exception.
         """
         raise exception.with_traceback(trace)
 

src/plumpy/processes.py

@@ -978,8 +978,8 @@ def close(self) -> None:
 
     # region State related methods
 
-    def transition_excepted(
-        self, _initial_state: Any, final_state: process_states.ProcessState, exception: Exception, trace: TracebackType
+    def transition_failed(
+        self, initial_state: Hashable, final_state: Hashable, exception: Exception, trace: TracebackType
     ) -> None:
         # If we are creating, then reraise instead of failing.
         if final_state == process_states.ProcessState.CREATED:

test/test_processes.py

@@ -242,10 +242,9 @@ def test_forget_to_call_parent(self):
                 proc.execute()
 
     def test_forget_to_call_parent_kill(self):
-        with self.assertRaises(AssertionError):
-            proc = ForgetToCallParent('kill')
-            proc.kill()
-            proc.execute()
+        proc = ForgetToCallParent('kill')
+        proc.kill()
+        assert proc.is_excepted
 
     def test_pid(self):
         # Test auto generation of pid